1. Field
The present disclosure relates generally to image processing and, in particular, to resolving closely spaced objects in images. Still more particularly, the present disclosure relates to a method, apparatus, and system for resolving a set of objects in an image of an area such that a determination as to whether any of the set of objects is an object of interest may be made and at least a position of any object of interest may be identified with a desired level of accuracy.
2. Background
Sensor systems may be used to detect and track different types of objects that move in an area. These different types of objects may include, for example, without limitation, aircraft, unmanned aerial vehicles (UAVs), spacecraft, satellites, missiles, automobiles, tanks, unmanned ground vehicles (UGVs), people, animals, and other types of objects. Further, these objects may be detected and tracked using different types of sensor systems. These different types of sensor systems may include, for example, without limitation, visible light imaging systems, electro-optical (EO) imaging systems, infrared (IR) sensor systems, near-infrared sensor systems, ultraviolet (UV) sensor systems, radar systems, and other types of sensor systems.
As one illustrative example, a sensor system may be used to generate still images or video of an area. These images may be used to detect and track objects of interest in the area. In some situations, two or more objects that are within close proximity in the area being observed may appear in a same region of an image. These objects may be referred to as a “cluster.” For example, when the lines of sight from a sensor system to two or more objects in the area being observed are within some selected proximity of each other, the portions of the image representing these objects may partially overlap such that the objects appear as a cluster in the image. In particular, when these objects are point objects, the portions of the image defined within the point spread functions for these point objects may partially overlap.
When the portions of an image representing these objects overlap by more than some selected amount in an image or in different images in a sequence of images, distinguishing between these objects and tracking these objects independently in the cluster in the sequence of images may be more difficult than desired. Some currently available methods for distinguishing between the objects in a cluster in a sequence of images may take more time, effort, and processing resources than desired. Further, these currently available methods may be unable to track movement of the objects with a desired level of accuracy. Still further, some of these currently available methods may be unable to resolve a cluster when the cluster includes more than two objects. Therefore, it would be beneficial to have a method and apparatus that take into account at least some of the issues discussed above, as well as possibly other issues.